Typewriting machine



April 23, 1935. H. A. AVERY I 3,998,829

" TYPEWRITI NG MACHINE I v Filed June 28, 1934 6 27 i 39 lei J j .1 3 @Z 2, 36 E 2Z7 Z7 12; Ii?

WW we) 0 ATTORNEYS framework of Patented Apr. 23, 1935 7 1,998,829 TYPEWRITING MACHINE Henry 'AIIen Avery, Groton,

& Corona Typewriters, Inc., Syra L. 0. Smith cuse; Yiga corporationof New York Applicationalarie 28,1934, Serial No. 732,865 11"Clai'ms. (Cl; 197 '-88) This invention relates to typewritingmachines and like machines having atraveling carriage-and. escapement mechanism for'thecarriage;

. The principal: objects of the invention are to ;v provide a simple, inexpensive and-.s'ilentlypper ating .escapement mechanism; to provide a silentlyoperating escapement mechanismof the type known as a reverse escapement in which substantially all of the letter: space feed-oft the carriage occurs on the down strokes ofthe keys; and to provide an: escapement' which will. silently control the feed of the carriage inletter'spacing: directionandxis so constructedas topermi't' silent returnof the carriage without releasing theicarriageirom the escapement 7 To theseends;v and to. other vends-which will appear from the following: descriptioniimdetail of a preferred. embodiment'of the. invention shown in the accompanying drawing, thesinventionconsists in the combinations of devices,- featuresof construction, and arrangements of parts-pointed out int the: appendedclaims'a' d set fortlr in the following description.

In. the drawing:

Fig. l is a sectional view'on: the line l--l of Fig.2.;

'Fig. 2'. isa fragmentary top planview of the machine, certain parts being brokenawa'yto more clearly show the improvements; and partsof' the escapement being shown in normal position;

Fig. 3 is a side elevation'of the escapement mechanism showing the dog rocker rocked from normal position to disengage the holding dogfrom the escapement wheel and engagethe step ping dogwith said wheel;

Fig. 4 is a bottom plan view of the escapementwith theparts in normal position as in Figs. 1 and 2; and

Fig. 5 is a bottom plan view of the escapementwith the dog rockerrocked as Fig. 3 and the stepping dog holding; the carriage arrested.

In the'accompanyi'ng drawing the invention is shown embodied in a well known typewriting-machine, only so much of which machine is illi1strated as is necessary for a full understanding of the invention.

The platen carriage l'=carries a platen (and travels transversely of the machine on a carriage bed 12- which forms a part of the stationary; the'machine, suitable ball bearings l3 being confined in raceways formed onthe carriage and bed. A shaft M extendsthrough a clearanceaperture in the bedand is journalled at its upper and. lowerends in a bracket 'l-5'='fixed to and mesheswith a feed rack of the dog' carrier overhanging a H held-to the carwith the carriage. A- toothed escapement wheel or circular escapement rack. I8

is fixed on shaft l4-below the bed; Thecarriag-e is-norma-lly urged letter spacing direction to-' 5 ward the left hand side of the machine by the usual spring drum and-draw band, not shown.

At therear ofthe escapem'ent wheel isa sheet metal-dog. rocker l9r having a flat body portion andtwo-pendant side arms; dog rocker are journalled on horizontalpivotslt carried by the bracket i5. ,A- dog rocker returrr spring; 21 ,i connected. with rocker and: bracket Iii-, normally holds astep edge =22 of -one ofthe side arms of the r riage to travel ker rocked down upon a stop lug. Zironbracket 15. The rocker is rocked, on the down strokesof the keys, upward and rearwardfrom theposition shown in Pigs; i and 2- to-that shown Fig. 3" by a suitableuniversal-*bar'mechanism', notshown. The improvements will nowbe described.

A flat sheet metal dog: carrier 24 lies fiatwiseonthe flat upper face of the main body portion: of the dog ro'cker. This'dogcarrier extends-foreand-aft of the machine and is heldto the-dog rocker by" an upstanding pivot bolt 2-5- having a-- nut 26-screwed: on its lower end.- The dog-carrieris pivoted intermediate its forward and rear ends to" provide a forward dog: carrying rear end wh'ichbears'on the dog rocker to assist in preventing canting' of the carrier relatively to the rocker, theforward or dog-carrying portionrecess 21 in-the forward edge ofthedog rocker. Swinging movementof the dog carrier 24' on itspivot in eitherdirection is yieldingly resisted by two opposed coiled spring 28 which extend transversely of the machine. Lugs 29 on the dog rocker extend inwardly from opposite-sides of recess 21'"into-- the outer ends of springs 2-8, and' lugs 30 on the dog" carrier 24- extend outwardly from theforwardend of the dog carrier-at opposite" sides of said carrier into:the inner ends of the: springs, the springs being, held inplace by the lugs and the dog. carrier being held: balanced inthe position shown in the several views by the two-opposed springs 2-8: The holdingdog 3I is-pivotally heldtothefor ward end of thedog carrier 24 atthe upperface of the carrier by an: upstanding pivotbol having a cylindrical'nut 33: screwed omits lower end below the dogcarrier. Holding dog. 34' has a nose 34 forward of its pivot, which=noseis-nor-- mallyiengagedz'with a: tooth of: the eseapement wheel; and said dog; has aportionfiflinrear of; 55 1 The side arms ofthe 10' its pivot normally held rocked against a stop stud 36 fixed to the forward portion of the dog carrier. A light spring 3! connected to one side arm of the dog rocker and to the dog 3| forward of the dog pivot normally holds part 35 of the dog against stud 38.

The stepping dog 38 is pivotally held at its rear end to and below the forward end of the dog carrier by an upstanding pivot bolt 39 whiclrhas a nut 43 screwed thereon above the dog carrier. Stepping dog 38 has a nose 4| at its forward end, which nose is normally disengaged from the teeth of wheel l8 and held rocked towardth right of the wheel tooth engaged by dog 3| by means of a light spring 62 connected to one side arm of the 3 dog rocker and to the dog 38 forward ;of the.

pivot of said dog. Extending forward fromthe pivoted end of dog 38 at the left-hand side of the dog is a stiff spring finger 43 normallyspaced to the right of nut 33 but engageable with said nut when the stepping dog is rocked toward the left side of the machine.

On the down stroke of a type key or of the space bar of the machine the dog rocker I9 is rocked upward and rearward by the usual universal bar path of the next following tooth of the wheel,

very slightly oifset toward the right-hand side of the machine relatively to the tooth-engaging edge. of the nose of dog 3|. aforesaid movement of the carriage is further cushioned, and the setting up of noise-producing vibrations and their transmission to the dog rocker and the stationary framework of the machine is further prevented, by the momentary yielding of the dog carrier 24 under the impact of finger 43 against stop nut 33. The dog carrier oscillates slightly on its pivot 25 under thisimpact but this oscillation lasts only for an infinitesimal period, the dog carrier being brought substantially instantly to rest in its normally balanced position (shown most clearly in Figs. 2, 4 and by the opposed balancing and centering springs 28 which ing the carriage by dog 3| is absorbed and silenced by the momentary yielding or oscillation of dog carrier 24 as in the case of the shock of arresting the carriage by dog 38.

The carriage may be returned without releasing the escapement, since the. teeth of wheel l8 The shock of arresting the direction of letter feed travel of the carriage,

thus preventing injury to the holding dog under such thrusts or impacts or when the machine is turned over on its lefthand side.

What I claim is: 1

l. Atypewriting or like machine having a carriage-feeding escapement wherein a dog rocker a toothed element to feed a carriage step-bystep, characterized in that the dogs are carried about an axis parallel to the second-mentioned axis, means-normally holding the dog rocker in a position in which the holding dog is engaged and a spring normally holding the stepping dogrocked away from its stop.

5. In a typewriting machine having a frame and a carriage traveling on the frame, a carriage escapement for letter-feeding the carriage comprising a toothed element which moves when the carriage travels, a dog rocker supported on the frame to rock about a fixed axis, a dog carrier pivoted on the dog rocker to swing about an axis extendingtransversely of said fixed axis, means yieldingly resisting swinging of the carrier in either direction about the second-mentioned axis, a holding dog and a stepping dog each pivotally held to the dog carrier to swing about an axis parallel to the second-mentioned axis, means normally holding the dog rocker in a position in which the holding dog is engaged with the toothed element and the stepping dog is disengaged from the toothed element, a holding dog stop on the dog carrier normally engaged by the holding dog and away from which said dog may be swung by the teeth of said toothed element during return movement of the carriage, a spring normally holding the holding dog to its stop, a stepping dog stop on the dog carrier, and a spring normally holding the stepping dog rocked away from its stop, said stepping dog having a resilient portion engageable with its stop when the stepping dog is rocked about its pivot by said toothed element in letter-feeding the carriage.

6. In a typewriting or like machine having a frame and a carriage traveling onthe frame, a carriage escapement for feeding the carriage step-by-step in one direction comprising a toothed element which moves when the carriage moves in said direction, a pivotally supported dog rocker, dogs co-active with the teeth of said toothed element to feed the carriage in said direction when the rocker is rocked about its pivotal axis, and a dog carrier upon which said dogs are mounted and which is supported on the dog rocker to rock with the rocker and to yield relatively to, the rooker'under impacts of the teeth of the toothed element upon the dogs.

'7. In a typewriting or like machine having a frame and a carriage traveling on the frame, a carriage escapement for feeding the carriage step-by-step in one direction comprising a toothed element which moves when the carriage moves in said direction, a pivotally supported dog rocker, dogs co-active with the teeth of said toothed element to feed the carriage in said direction when the rocker is rocked about its pivotal axis, a dog carrier upon which said dogs are mounted and which is supported on the dog rocker to rock therewith when the rocker is rockedand to shift relatively thereto under impacts of the teeth of the toothed element upon the dogs, and opposed spring means for yieldingly resisting shifting movement of the dog carrier relatively to the rocker and normally holding the carrier balanced therebetween in predetermined relation with the rocker.

8. In a typewriting or like machine having a frame and a carriage traveling on the frame, a carriage escapement for feeding the carriage step by step in one direction comprising a toothed element which moves when the carriage moves in said direction, a pivotally supported dog rocker, dogs co-active with the teeth of said toothed element to feed the carriage in said direction when the rocker is rocked about its pivotal axis, and a dog carrier dogs are mounted and which is pivotally held to the rocker to swing relatively to the rocker under impacts of the teeth of the toothed element upon the dogs, and spring means for yieldingly resisting swinging of the dog carrier relatively to the rocker.

9. In a typewriting or like machine having a frame and a platen carriage which travels transversely of the frame, the combination of a toothed element which moves when the carriage moves in one direction, feed dogs co-active alternately with the teeth of said element to feed the carriage insaid direction, a dog rocker oscillatable about an axis fixed relatively to said element to cause said dogs to alternatively engage with the teeth of sad element, a dog carrier pivoted on said rocker to swing about an axis extending transversely of the rocker axis and carrying said dogs, and spring means yieldingly resisting swinging of said dog carrier in either direction about said second-mentioned axis and adapted to restore said carrier to one and the same relative position rocker with either of said dogs engaged with a tooth of said toothed element.

10. In a typewriting machine having a frame and a platen carriage which travels transversely of the frame, the combination of a toothed element which moves when the carriage travels in one direction, feed dogs co-active alternately with the teeth of said element to feed the carriage step by step in said one direction, a'dog rocker oscillatable about an axis fixed with respect to said element, a dog carrier upon one end of which said dogs are mounted and which is pivoted intermediate its ends on the dog rocker to swing under impacts of teeth of said element upon the dogs, said carrier having its other end swingable over and in contact with a fiat face of said rocker, and spring means for yieldably holding said carrier swung about its axis in predetermined relation with said rocker when either dog is engaged with a tooth of said toothed element.

11. In a typewriting or like machine having a traveling carriage, an escapement mechanism for the carriage comprising a toothed element which moves when the carriage travels in one direction, a dog rocker pivotally supported to swing relatively to said element about a fixed axis and in a fixed plane, a dog carrier pivoted on the rocker to swing under impacts of teeth of said element upon dogs carried by said rocker, a holding and a stepping dog carried by the dog carrier, and means for yieldably holding the dog carrier in a predetermined relation with the dog rocker and restoring the dog carrier into said relation after impact of a tooth of said element with either dog and while the dog is still engaged therewith, said dogs being alternatively engageable by teeth of said element to feed the carriage step-by-step in said one direction as the rocker is rocked.

' HENRY ALLEN AVERY.

with respect to the dog upon which said 

